Crossover- impedance matching, level matching, resonance matching and harmonic balanc

[kapvin]

Re: Crossover- impedance matching, level matching, resonance matching and harmonic ba

no man you got it misunderstood im not talking about breakup im talking about ridges in the waterfall plot. Aluminium is light and rigid for the decent pistonic behaviour but the energy residue in aluminium is high than silk domes thats the problem. Thats why silk domes are preferred and dont have any color associated with it.

Simple just tap a little with a match stick to the aluminium dome and try to hit it to the silk dome you will understand why.

you can see the ridges at 4k to 6k..
http://www.stereophile.com/images/archivesart/N33fig8.jpg

Dear Hifi Guru,

do you understand what pistonic behaviour means?

I am also a bit amazed by your matchstick explanation. do you also see if car shock absorbers are effective by compressing them by hand?

finally, just for fun, I am linking 2 CSD plots. identical motors, difference only in Dome material. 1 silk, 1 metal

Can you tell which is which, and which is better and why?

 

[kapvin]

Re: Crossover- impedance matching, level matching, resonance matching and harmonic ba

The top one is definitely a silk dome and better the bottom one is somewhat better than aluminium dome if im not wrong it must be titanium dome.

The top is better because look at the ridges between 2k and 3k between 1ms to 2.5ms (Most sensitive region for human ear)

so what does that signify is the mechanical energy which is being imparted to the dome will be converted in to sound energy but a partial energy is stored for short duration of time in metals and they release it after few milli seconds. Now here you see only single sweep but what happens on a complex multi tone musical signal the ridges form everywhere scattered thats why metallic domes dont sound good.

Yes we do understand pistonic behaviour and we are very much aware of what sort of pistonic behaviour results with what sort of problems it creates.
read this document completely to get an idea what sort of problems generally raises in pistonic behaviour and non linearities created because of them.
http://www.klippel.de/uploads/media/Loudspeaker_Nonlinearities–Causes_Parameters_Symptoms_01.pdf

The reason why i said you to try with match stick is that in order to measure using right tools needs some pro setup like impulse response and step response the simple signature identification can be done just by a tap sometimes for a midrange or woofer just a tap would generally signify its basic signature but for metal domes since tap damages it said to try with match stick...! simple tip..

I purposely left the links in with the tweeter names. congrats, you can google,

I'd say that you should know that to read a CSD plot you need to look at the fundamental first and then the decay. also you need to look at the CSD from a passband perspective. i would say 2 things.

1. there is very little difference between them.
2. in the upper frequency range the 1st is actually ringing more. (remember to look at the fundamental). as it is in 3-4k range. and the 6khz+ range.

since you insist on referencing klippel documentation, (pg 5) I'd like to point out that 8 out of the 9 points that affect non linearity are motor or enclosure driven, and only 1 has anything to do with cone/ dome material.

it is an easy mistake to get biased against metal domes based on peerless alu tweeters. those are bad tweeters. period. and not only because of the dome material. as is almost all the stuff that is sold by peerless in India

the broader point that i was making, and surprisingly backed up by the documentation you provided, is that motor design & enclosure design (venting on the tweeter) plays a larger role than just simply the dome material choice.

Metal drivers may not be for everybody, (certainly not immature DIY novices), but with the right crossover design and right driver pairing, they are subjectively the most articulate and measurably no better or worse than any other material.


I don't know you or your credentials apart from your self claim to be a hifi guru (and I am not); but there are impressionable novices out here, who hang on to every word every so called guru says.

Making sweeping statements such as this is not the way I have seen real gurus act on any other forum.

best wishes